Tubular Turbine Hydropower Plant Comes Online

08/01/2012 | Sonal Patel

Albania this June inaugurated its first major hydropower project since the early 1980s, bringing online Ashta I, the first of two run-of-river plants with a combined capacity of 53 MW. At the inauguration ceremony, Albania’s Prime Minister Sali Berisha called the plant “a novelty” because it is the largest in the world to use advanced tubular turbines technology.

The twin plants are located on the Drin River near the northern city of Shkodra. The tailrace of Ashta I consists of a 6-kilometer-long canal connecting the two plants and a diversion channel connecting the plant with the Drin River. The Ashta II plant has a similar arrangement, and its tailrace will be connected to the Drin river by a short canal. Each plant is equipped with 45 ANDRITZ Hydromatrix TG units—small steel turbine modules the size of a telephone box—mounted in one row at the upstream face of a concrete gravity dam structure (Figure 5). ANDRITZ describes these axial-type propeller turbines as having bulb-style generators. They can be raised individually for service purposes. The accompanying draft tubes are embedded in the newly built dam structure.

5. Tubular turbine technology. The Ashta I and II run-of-river hydropower plants in northern Albania, which will total 53 MW, feature the largest array of Hydromatrix units, which are small steel turbine modules mounted in a row at the upstream face of the concrete gravity dam structure. This image shows Ashta I under construction in 2011. Courtesy: Verbund

Austria’s largest utility, Verbund, which obtained the concession for construction and 35 years of operation of the €160 million ($198 million) Ashta plant in 2008, says that the Hydromatrix technology, used for the first time in Europe on a large scale at Ashta, enables “an especially efficient utilization of water.” One “outstanding” aspect of the Hydromatrix concept, says Verbund, is its flexibility with regard to the plan arrangement due to the compact size of the turbine generator equipment. “The resulting minimization of the required civil services has significant advantages in terms of space requirements, thus considerably reducing the project’s environmental effects and construction costs.”

The project is significant for the region, as Albania’s Energy Association pointed out, because Albania uses just 40% of its hydro potential, and though it imports much of its power, it aspires to become a regional electricity powerhouse. Although hundreds of new power plants are in the pipeline, several projects have been riddled with tendering difficulties involving allegations of corruption.

All the power generated by Ashta will be purchased by Albanian power company KESH, the state-run energy provider. The contract term will then either be extended, or the electricity will be sold on the open market.

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